Hot air furnace



Au 27, 1940. LENGYEL 2,212,666

HOT AIR FURNACE Filed Dec. 15, 1939 INVENTOR fiu b ATTORNEYS Patented Aug. 27, EQQQ artiste UNl'iEDS'iA'iES earsur orrica Carl Lengyel, Bufialo, N. Y.

Application December 13, 1939, Serial No. 309,64?

2 Claims.

This invention relates to improvements in a hot air furnace of the type which includes a hollow radiator or drum through which hot gases are conducted from a 'combustion chamber to a chimney or flue and a housing forming an air chamber and'having a lower upright wall which surrounds the side of the radiator and adjacent parts of the heating apparatus and a top or dome which extends inwardly from the side wall over the entire radiator and is separated throughout its entire width from the upper side of the radiator by an intervening air space.

In the operation of such furnaces as heretofore constructed the hot gases passing upwardly from the combustion chamber first engagewith the central part ofthe housing top or dome and then are deflected laterally thereby in the air space between the upper side of the radiator and to the underside of the dome toward the air outlets formed in the marginal parts of the dome through which they escape to the chimney or flues leading to the outer atmosphere.

Inasmuch as the gases upon rising from the combustion chamber are in their hottest condition and therefore operate with the greatest intensity on the central part of the upper side of the radiator it follows that the air immediately above this part of the radiator is also heated to the greatest extent. In prior furnaces undue heating of the air in the room immediately above the central part of the dome has been prevented by making this central part of the housing dome of downwardly dished form and filling the same with sand which operates as an insulator to prevent excess heating of the respective part of the housing dome and the external air adjacent thereto.

This construction is objectionable inasmuch as a dead body of air is constantly. present between the central parts of the radiator and the housing dome which, owing to its low heat conducting capacity, interferes with the transference of heat from this part of the radiator to the stream of air flowing upwardly from the marginal parts of the radiator through the corresponding parts of the air space between the radiator and housing dome to the air outlets of the latter, and therefore reduces the efliciency of the furnace accordingly.

It is the purpose of this invention toprovide a hot air furnace of this character with simple and efllcient means whereby the dead air space immediately above the central part of the radiator is eliminated and heat from this part of the latter is transferred to-the stream of air passing through the annular space between the marginal parts of the radiator and the housing dome, thereby not only efiecting a saving in fuel but also increasing the speed of the air which is being heated and enabling rooms to be warmed 5 more rapidly than has been possible heretofore.

In the accompanying drawing: p 'j Fig. 1 is a vertical section of a hot air furnace embodying one form of this invention.

Fig, 2 is a horizontal section, on an enlarged 11 scale, taken on line 22, Fig. 1.

Fig. 3 is a fragmentary vertical section, on an enlarged scale, taken on the correspondingly numbered line in Fig. 2.

In the following description similar characters 15 of reference indicate like parts in the several views of the drawing: p

Although this invention may be embodied in hot air furnaces which may vary in details of construction, that shown in Fig. 1 is suitable and comprises a heating apparatus having a lower pit I0, a fire pot H which is arranged above the pit, and in which the fuel is burned, a combustion chamber I2 which receives the gases from the fire pot and in which the combustion of'the same 26 is completed, and a hollow radiator or drum which is arranged above the combustion chamber and which has a central section l3 constructed in the form of a cap having a closed crown or head It and an open lower end through 30 which it receives the hot gas from the upper end of the combustion chamber, and an annular heat distributing channel i5 which surrounds said cap-shaped central section l3 and is connected on its inner side with the side wall iii of the radiator cap by a radial flue ll, while its outer side is provided with a pipe or outlet ill for the smoke or products of combustion which are delivered to a chimney or flue leading to the outer atmosphere.

When burning hard fuel, such as wood or coal, a grate 19 is employed between'the fire pot II and the pit and the latter in this case serves to receive the ashes of the burnt fuel, but if a fluid fuel is burned in the fire pot, such as oil or gas, then the grate may be omitted.

An ,air chamber or jacket is formed around the side of the heating apparatus and over the marginal part of the same which is adapted to receive the air to be heated and conduct the same to pipes leadingto the places to be heated. This air chamber is formed by a housing or Jacket comprising a lower body or upright wall 20' of circular form surrounding the side of said ash pit, fire pot, combustion chamber and radiator channel but spaced therefrom and having an air inlet' 2| on its lower part, and an annular outer top or dome section 22 extending inwardly from the upper end of the body-or side wall and overhanging the marginal part of said radiator but spaced therefrom and provided with one or more air outlets 23 through which the hot air is discharged from the air chamber and then conducted by suitable piping or conduits to the rooms to be heated.

The improvement forming the subject of this invention consists generally of deflecting means which extend from the top of the housing to the upper side of the radiator so as to avoid the formation of a dead air space between the cen-- tral part of the housing top and the central part of the radiator, thereby compelling all of the air which enters the lower part of the air jacket to flow in the form of a live stream upwardly along the exterior of the heating apparatus and to the hot air outlets of the housing top, whereby the flowing speed of the air is increased and the rooms which are served will be heated more rapidly. The air deflecting means for accomplishing this purpose may be varied, those shown in Figs. 1, 2 and 3 being one form which is suitable and constructed as follows:

The numeral 24 represents the upper section of an air deflector which is preferably constructed of metal in the form of a downwardly tapering or conical ring section 24 which is secured at its upper edge to the inner edge of the annular marginal top 22 of the housing by means of screws 25 or otherwise and provided at its lower end with a downwardly projecting cylindrical collar 26, and an upright cylindrical lower neck section 21 of sheet metal which has the upper'part of its periphery slidingly engaged with the bore of said collar 21 while its lower end is provided with a plurality of contact lips or fingers 28j which are preferably bent alternately in opposite directions from the lower deflector section and frictionally engaged with the marginal part of the metal head or crown M of the cap I3 forming the central section of the radiator. Due to the presence of the deflector between the central parts of the radiator and the top of the housing, the heated air which rises in the annular space between the outer side of the heating apparatus and the inner side of the wall of the housing is unable to gather in the form of a dead body between the central parts of the radiator and housing top and instead is instantly directed to the air outlets of the housing top, thusexpediting the flow of hot air and causing the heating effect 'of the same to be accomplished more rapidly.

Owing to the metallic contact of the deflector with the central cap of the radiator and the upwardly flaring form of the same toward the air outlets of the hou' ng top, heat is transferred from the radiator to this deflector and as the latter is arranged at the upper end of the air' top extending from the side wall over themarchannel, and the combustion chamber, fire pot and pit. v

As appears in Fig. 1, the upper and lower sections 24 and 21 of the air deflector are of tubular form and, together with the crown Id of the 5 I central cap l3 of the radiator, produce a receptacle which is closed at the side and bottom and open at the top. Within this receptacle is placed a filling 29 of heat insulating material, such as rock wool or mineral wool, thereby preventing radiation of heat from the central part of the radiator to the external atmosphere immediately above the same and causing the tubular members 24, 21 of the air deflector to operate as the sole means which transfer heat from the central part of the radiator to the annular body of air which surrounds the deflector within the housing and thereby causes the air to be heated more emciently and economically.

The form-of air deflector shown in Figs. 1 20 and 2 is more particularly suited for attachment to furnaces of different makes which have been installed and in which the distance between the central parts of the radiator and the housing dome may vary considerably, in which case the upper and lower tubular sections 24, 27 ,of the deflector may slide relative to one another in the manner of a telescopic joint for shortening or lengthening the deflector as much as required for adapting the same to the particular distance between the radiator and housing dome of the respective furnace.

This air deflector is not only very simple in construction and low in cost but the same can also be easily applied to furnaces already in use as well as new furnaces while being built and its use efiects a considerable economy in fuel consumption and expedites the heating operation.

I claim as my invention:

1. A hot air furnace comprising a combustion chamber in which the hot gases rise, a radiator arranged above the combustion chamber and receiving the hot gases therefrom, a housing having a side wall extending around the side of the combustion chamber and the radiator, a top extending from the side wall over the marginal part of the radiator and having an air outlet, and a tubular air deflector having a downwardly tapering upper section which is connected at its upper edge with the central part of said housing top and a cylindrical lower section which slides at its upper end in the lower end of said tapering section and engages its lower end with the central part of said radiator.

2. -A hot air furnace comprising a combustion chamber in which the hot gases rise, a radiator arranged above the combustion chamber and receiving the hot gases therefrom, a housing having a side wall extending around the 'side of the combustion chamber and the radiator, a

ginal part of the radiator and having an air 1 outlet, a tubular air deflector having a downwardly tapering upper section which is connected at its upper edge with the central part of said housing top and a cylindrical lower section which slides at its upper end in the lower end of said tapering section and engages its lower end with the central part of said radiator, and a filling of rock wool arranged in said deflector.

' CARL LENG YEL. 

